"A person is guilty of an attempt to commit a crime when, with intent to commit a crime, he engages in conduct which tends to effect the commission of such crime" (Penal Law § 110.00). We conclude that the evidence here is insufficient to support the jury's finding that defendant attempted to cause injury "by means of * * * a dangerous instrument" (Penal Law § 120.05; see, Matter of Lavasia V., 237 A.D.2d 183). A dangerous instrument is defined as "any instrument, article or substance * * * which, under the circumstances in which it is used, attempted to be used or threatened to be used, is readily capable of causing death or other serious physical injury" (Penal Law § 10.00 [emphasis supplied]).